Heavy rains have fallen on Philly on 11 days since Dec. 1, about triple the average
Since Dec. 1, at least an inch of rain has fallen on 11 different days in Philly. The average is for that amount of rain to fall in fewer than four days.
The soakings of the last few days may seem like business as usual these days, but this has been quite an extraordinary run of weather here and elsewhere in the Northeast.
During the reign of rain that began on Dec. 1 — in which seven months’ worth of precipitation has fallen — an inch or more has been measured officially at Philadelphia International Airport on 11 different days.
The long-term average for the period is fewer than four days. The 1.13 inches through 5 p.m. Wednesday pushed the total since Dec. 1 past 25 inches, more than 10 inches above normal.
It’s isn’t just us. The Northeast was significantly wetter than normal in the Dec. 1-Feb. 29 period, and in March, several cities set records, including Atlantic City and Caribou, Maine. For Philly, it was the No. 4 wettest, according to the Northeast Regional Climate Center.
What’s behind the downpours? The El Niño warming in the tropical Pacific, in which overheated waters have affected upper-air patterns and have influenced precipitation patterns across the country, said Nat Johnson, researcher with the Geophysical Fluid Dynamic Laboratory, in Princeton.
Usually, however, it’s wetter in the Southeast during El Niño, he said, and parts of the South have been drier than expected. The rains around here “are more of a mystery,” he said.
Other suspects would be the changing climate, and what Johnson called “the most frustrating” possibility — the internal chaos of the atmosphere.
Whatever the cause, the rains are due to shut off by the weekend, and so far the sky prospects for Monday’s eclipse are looking bright.